docs: def metadata(self):
          """
          Retrieve the metadata info for this prefix
  
          Returns:
              dict: metadata info
          """
          if self._metadata is None:
              try:
                  with open(self.paths.metadata()) as metadata_fd:
                      self._metadata = json.load(metadata_fd)
              except IOError:
                  self._metadata = {}
          return self._metadata